Department of Microbiology, Yale University School of Medicine, New Haven, Connecticut, USA.
Planta. 1972 Dec;107(4):351-67. doi: 10.1007/BF00386396.
A method has been developed for the isolation of chloroplasts from Euglena gracilis grown under mixotrophic conditions. This method utilizes sucrose density-gradient centrifugation in the AXII zonal rotor and allows the rapid preparation of large amounts of chloroplasts free from contaminating whole cells and other cytoplasmic materials. The majority of the isolated chloroplasts appear intact in phase contrast and electron micrographs. The purified chloroplast fraction contains DNA, the major species of which has a density of 1.682 g/cm(3). The species of DNA having a density of 1.707 g/cm(3) seemed to result from the presence of contaminating nuclear fragments which could be removed by isopycnic flotation.
已经开发出一种从混合营养条件下生长的眼虫中分离叶绿体的方法。该方法利用 AXII 区带转子中的蔗糖密度梯度离心，可以快速制备大量无杂质的完整叶绿体，避免了与完整细胞和其他细胞质物质的污染。在相差和电子显微镜下，大多数分离的叶绿体看起来完整无损。纯化的叶绿体部分含有 DNA，其主要物种的密度为 1.682 g/cm(3)。密度为 1.707 g/cm(3)的 DNA 物种似乎是由于存在污染的核片段所致，可以通过等密度漂浮去除这些核片段。
